Qualité de l'air à La Réunion

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly/idempotent/openWorld, so the safety profile is covered; the description adds meaningful context beyond that — the index scale, the responsible pollutants, the data source, and that results cover today and tomorrow. It does not discuss caching or freshness latency, which keeps it from a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The core capability is front-loaded in the first clause, and the example phrasings are genuinely useful for matching user intent. The bilingual tail is economical, though the run-on enumeration of place types makes it slightly denser than necessary.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With a single fully-documented optional parameter and no output schema, the description does the needed work by explaining what the index values mean (1 bon à 6 extrêmement mauvais) and what pollutants are reported. Missing only an explicit note on output shape or update cadence.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the single optional 'lieu' parameter is already well documented with examples. The description reinforces this by stating that an empty value means the whole island, adding slight value over the schema rather than repeating it.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names the specific resource (indice ATMO par commune à La Réunion), the temporal scope (jour et lendemain), the data producer (Atmo Réunion), the scale (1–6) and the pollutant breakdown. An agent can immediately distinguish it from weather siblings like meteo_actuelle or prevision_meteo.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Concrete example queries (« l'air est pollué à Saint-Louis ? », « je peux faire du sport dehors ? ») make the intended use clear, and it states the default behavior when no location is given ('Sans lieu : toute l'île'). It does not explicitly say when to prefer this over vigilance_meteo or prevision_meteo, so it stops short of full routing guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.